Her parents, Alexandra (Christos) and Constantine S. Dukakis, were Greek, her father from Anatolia and her mother from the Peloponnese. Her first cousin is politician Michael Dukakis (their fathers were siblings).

Olympia was married to actor Louis Zorich, until his death, with whom she has three children.

Olympia’s paternal grandfather was Stylianos/Stelianos Dukakis (the son of George Dukakis and Mary). Stylianos was born in Pelopi, Greece.